Under Armour shares are slammed after its stunning growth streak ends

Under Armour has long promised a lot and then delivered. On Tuesday it didn’t come through, and now investors need to understand the costs of that impressive winning streak.

The sportswear maker’s 26-quarter string of 20%-plus sales growth came to an abrupt halt when it said fourth-quarter sales grew by only 12%. Under Armour also lowered its 2017 revenue-growth outlook to between 11% and 12% from the low-20% range and said operating income would fall.